Rolling mill system

ABSTRACT

A rolling mill includes an arrangement of a plurality of grooving rollers or rolls in a row with forming rollers which are carried in a mounting frame for operation on a continuously fed strip or plate to bend the plate into a tubular configuration which is fed as formed into association with the rolls of the grooving stands. A feature of the construction is that a single forming roller and two sets of upper and lower forming rollers are arranged on a frame which includes a pivotally mounted lower frame member carrying the lower rollers and a pivotally mounted upper frame member carrying the upper rollers. The frame members are arranged in a rectangular configuration and mounted for pivotal movement about a lower end adjacent the grooving stands. The opposite end is connected to a member which may be moved vertically by suitable driving mechanism to change the elevation of the entire forming roller sets carried in the frame. In addition, the upper rollers of the two roller sets which are spaced further away from the grooving stands than the single forming roller may be shifted so that they may be lifted upwardly from the material being operated upon.

United States Patent [54] ROLLING MILL SYSTEM 11 Claims, 5 Drawing Figs.

s2 u.s.c|.. 72/181 511 lnt.Cl B2ld5/08 so FieldniSearch 72/176 [56] References Cited UNITED STATES PATENTS 1,032,634 7/1912 Taeschner et al 72/181 X 1,184,947 5/1916 Gossettetal..... 72/181 X 1,322,984 9/1931 Watkins 72/181 X 2,248,088 7/1941 Kane 72/181 Vassar 219/59 ABSTRACT: A rolling mill includes an arrangement ofa plurality of grooving rollers or rolls in a row with forming rollers which are carried in a mounting frame for operation on a continuously fed strip or plate to bend the plate into a tubular configuration which is fed as formed into association with the rolls of the grooving stands, A feature of the construction is that a single forming roller and two sets of upper and lower forming rollers are arranged on a frame which includes a pivotally mounted lower frame member carrying the lower rollers and a pivotally mounted upper frame member carrying the upper rollers. The frame members are arranged in a rectangular configuration and mounted for pivotal movement about a lower end adjacent the grooving stands. The opposite end is connected to a member which may be moved vertically by suitable driving mechanism to change the elevation of the entire forming roller sets carried in the frame. In addition, the upper rollers of the two roller sets which are spaced further away from the grooving stands than. the single forming roller may be shifted so that they may be lifted upwardly from the material being operated upon.

ROLLING MllLL SYSTEM SUMMARY OF THE INVENTION This invention relates, in general, to the construction of metallurgical-forming devices, and, in particular, to a new and useful rolling mill for forming a continuous tube having several forming rollers aligned with a grooving stand having several grooving rolls and to an adjustable forming roller frame mounted to permit angular adjustment of the forming rollers.

In the known rolling mills, the steel strip to be deformed into a continuous tube passes through a number of Fixed stands with rigidly set rolling gaps between roller pairs which are employed for profiling. Due to the usual thickness, tolerances of the various strips uneven stresses appear on the strip edges during the passage of the rolling material through the rigidly set rolling gap. Different mechanical and geometrical values in the strip edge zones must be maintained for adequate welding of the tubes particularly in respect to thin wall tubes, the manufacture which is most likely to involve the risk of defective welds. As tests have shown, steelstrip is deformed best into a split tube if it can move up to the first rounding grooving stand freely, that is, without forced clampmg.

The invention.is based on the realization that the tube can be best formed in the above manner and, therefore provides a rolling mill arrangement which does not require a rigid roller adjustment with all of its accompanying disadvantages. In accordance with the invention, the arrangement comprises at least two forming roll sets arranged at a defined distance ahead of the grooving stands. The forming roll sets include upper and lower forming rollers arranged on a coupling member or frame which may be adjustably positioned at a desired converging angle toward the grooving stand. The upper forming rollers may be lifted out of the profile of the rolling material after the passage of the head of the rolling material up to the first grooving stand. The lifting may be accomplished by means ofa fluid pressure operated cylinder and piston combination connected to the upper mounting frame support carrying the upper forming rollers. The upper frame support is connected to an individually adjustable guide arm actuated by a fluid pressure operated cylinder and it may be displaced vertically to shift the location of the two upper rollers simultaneously, in addition to the whole set of forming rollers, including the lower rollers which cooperate with the upper rollers and one additional lower forming roller, are mounted in a rectangular frame which is pivoted at its lower end which is adjacent the grooving stand. The whole frame with all the rollers can be moved together upwardly or downwardly about the frame mounting pivot. In this way, the angle of approach to the rollers of the grooving stands may be controlled.

The advantage of the arrangement of the invention is that the steel strip or plate may only pass through two forming roll stands for deformation. This permits a simple inexpensive and also a more compact division of the rolling mill into a forming roll and a grooving unit. The rolls of the film rolling stands have the function within the frame work of the entire rolling mill of preshaping the first yards of the'strip or plate in such a way that its introduction into the first round pass is possible. The rolls of the forming roll stands are lifted after the introduction of the strip head into the first grooving stand by means of a controlled lifting device so that the strip may be introduced into the grooving rolls freely to carry out the remaining forming operation.

A further important advantage of the invention is that the relative velocity of the driven forming rolls is eliminated, so that an undamaged tube surface is obtained. A further advantage results during the passage of the crooked or sabered" strips which is the possibility of the free swinging of the sabers even before the closed round pass is encountered to ensure a steady run of the rolling mill plant and the elimination of the possible staggered edges. Since the additional stands, gears and motors necessary in the known rolling mills are dispensable it is possible for the first time, according to another feature of the invention, to shorten the forming length of the plant. This shortening may be up to the exact distance between the last forming rolls supported in the coupling member and the first grooving stand or a distance of about four times the diameter of the finished rolled split tube.

The simple and inexpensive design, particularly of the mounting frame or coupling rectangle carrying the upper and lower rollers of the forming roller sets provides a very simple arrangement for pivotally mounting the forming rollers adjacent the grooving stands.

A further feature of the invention is the arrangement which permits the handling of the elongated strip edges in a simple and easy manner. The strip edges of the plate cover longer distances during the deformation to the tube than the centerline of the plate. The result is the forming of corrugations and dents particularly in thin wall tubes in the range of the welding table and this produces waste. This inconvenience is eliminated by the invention by use of suitable height forming cams which eliminate harmful tensile stresses and the strip edges in a very inexpensive manner. The forming plant is therefore designed according to the invention so that each necessary contour cam can be continually adjusted in accordance with the different tube dimensions and qualities and, in this manner, it is possible to adjust the forming plant using a known adjusting device at the strip inlet. The adjusting range is so selected that the higher elevation of the strip inlet bears a relationship to the center axis of the grooving stand of about 5/10 of the diameter of the tube which is formed.

A further advantage of the arrangement of the invention is that all units necessary for the forming process are moved during the adjusting operation thus providing the condition that the necessary fine adjustments can be effected during the current production. With the invention, it is also possible to ad just even negative forming cams under the mill floor to produce an extremely thin wall tube, that is, one having a ratio of all thickness to diameter which is greater than 1 to 100.

Accordingly, it is an object of the invention to provide an improved rolling mill arrangement wherein a sheet of material is fed to a plurality ofgrooving stands through a forming stand arrangement having means for adjusting at least the upper rollers of the stands so that they may be lifted off the material after the head is delivered to the grooving stands.

A further object of the invention is to provide a mounting arrangement for the forming rollers ofa plurality of roller sets, the lower rollers being carried on a frame which is pivoted at a lower end and the upper rollers being carried on an adjustable frame member which may be moved upwardly and downwardly independently of the lower rollers, but which also may be pivoted with the pivotal movement of the frame.

A further object of the invention is to provide a forming roller frame mounting arrangement comprising a rectangular frame, the lower member of which carries the lower forming rollers, the upper member of which carries the upper forming rollers, the upper member being pivotally mounted on a side member, the opposite side member having an adjustable arm which may be controlled by a fluid operated cylinder, for example, the entire frame being pivotally mounted at a lower end and being movable by an adjustment member connected to the opposite end.

A further object of the invention is to provide a rolling mill arrangement for forming tubular elements particularly thin wall tubes which is simple in design, rugged in construction, and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.

BRlEF DESCRIPTION OF THE DRAWINGS ln the drawings:

FIG. 1 is a schematic side elevational view of a rolling mill having several forming and grooving rolls constructed in accordance with the invention;

FIG. 2 is a section taken along the line ll-ll of HG. 1;

FIG. 3 is a view similar to FIG. 2, but with the upper forming roll shown in an engaged position;

FIG. 4 is a section taken along the line lV-lV of FIG. 1', and

FIG. 5 is a top plan view of the device shown in Fit]. 1.

DETAILED DESCRlPTlON OF THE PREFERRED EMBODlMENT Referring to the drawings, in particular, the invention embodied therein comprises a rolling mill having a grooving stand portion generally designated 50 which is arranged directly adjacent a forming stand portion generally designated 52. The grooving stand portion 50 includes individual stand sets 1, 1a and lb each including upper rollers 54 and lower rollers 56 which engage the workpiece R after it has initially fallen into a substantially completed cylindrical shape.

ln accordance with the invention, the forming stands 52 are arranged directly adjacent the grooving stands and it comprises rectangular side frame portions generally designated 5 and 6 which support individual forming stands comprising a single forming roller 4, a forming roller set 2 and 2a and a forming roller set 3 and 3a. The frames 5 and 6 converge in a direction of the feed as indicated by the arrow in FIG. 5. Each coupling frame 5 and 6 comprises an upper coupling member 5a and a lower coupling member 5b and side coupling members generally designated 70 and 7b. The complete forming stand section, including the frames 5 and 6, are pivotally mounted on a pivot axle 8 carried on a bracket 58 ofa foundation or flowing 60. Shifting the whole forming stand assembly 52 may be carried out by a pivoting mechanism which includes a motor 9 driving through gearing 11 to a threaded member which may be moved vertically and which is connected at its upper end to an extension 62 of the frames 5 and 6.

A feature of the construction is that the lower rollers 4, 2a and 3a are rotatably supported on extensions of the coupling members or lower supports 5b and 6b of the frames 5 and 6, respectively, whereas the upper rollers 2 and 3 are supported on downward extensions of the adjustable coupling elements or upper supports 50 and 6 a of the frames 5 and 6, respectively. The upper supports 5a and 6a are pivotally mounted on a pivot pin 64 at the upper end of a coupling arm or side arm 70 The opposite end or arm 7 may be shifted upwardly and downwardly by actuation of a fluid cylinder 66 which, together with a piston rod 68, forms the side arm 7. The piston rod 68 may be shifted inwardly and outwardly in respect to its associated cylinder by actuation of the cylinder 66 through a suitable fluid control (not shown) to shift a piston (not shown) connected to the piston rod 68 as desired in order to effect the proper positioning of the coupling arms 5 and 6 and the rollers 2 and 3 which are supported thereby.

A workpiece W is fed from a roller conveyor 70 and it may comprise a flat steel sheet of rolling material which enters the forming stand section in a substantially flat condition and an elevation above the central axis M of the grooving stand portion 50. The whole forming stand assembly 52 may be shifted by actuating the motor 9 to provide for the shift from the axis of the workpiece W on the roller conveyor 70 to the central axis M of the grooving stands 50. The angle at which the rol lers 4, 2 and 2a and 3 and 3a are located for shifting the workpiece W into the grooving stands 50 is fixed by maintaining the elevational difference 05 D, i.e., preferably from 0.5 times the diameter of the finished rolled split tube R which is formed.

In order to prevent bending of the strip edges when extremely thin wall thickness of the rolling material is employed, a plurality of guide rollers 12 are arranged along each side of the workpiece W as it passes through the forming stands 52. The rollers l2 are arranged to provide a forming profile abutting on the material W which corresponds to the ideal forming cam of the tube.

As soon as the head of the workpiece W which has been preshaped in the forming roll stands 3 and 3a and 2 and 2a enters into the grooving stands 50, the upper forming rolls 2 and 3 are lifted out of the preshaped material W by means of the fluid pressure operated cylinder 66 which is effective to shift the coupling arms 5a and 6a upwardly. When this is done the material W can run freely inside the forming roll stand. The lifting device 66 is advantageously started automatically by means of an electric pulse control (not shown).

When the apparatus is to be used to form tubes of different dimensions or when the forming height cam of the rolling material W in the forming roll stand 52 is to be changed, the lower coupling members 5b and 6b of the coupling frames 5 and 6 are adjusted in height by pivoting the whole frame assembly about the pivot 8 using the driving motor 9.

With the invention, adjustment of the forming stand 52 may be effected to shift all of the bottom rollers together with the top rollers at the same time in order to adjust the downward angle of feed from the roller conveyor to the grooving stand or the top rollers may be lifted out from the material so that the material will run free in its feed from a flat sheet roller form on a roller conveyor into the grooving stands which can be done after an initial forming of the sheet into a tubular configuration is carried out.

What l claim is:

l. A rolling mill system for forming tubes, comprising a grooving stand having a plurality of upper and lower grooving roll sets between which a partly formed tubular workpiece is directed, a forming roll stand assembly including a mounting frame having an upper frame member and a lower frame member, said mounting frame being pivotally mounted adjacent the end thereof which is adjacent said grooving stand, a plurality of lower forming rollers mounted on said lower frame member, an upper forming roller associated with each of said lower forming rollers carried by said upper frame member, said upper frame member being pivoted at its one end and having an opposite end facing said grooving stand movable upwardly and downwardly to respectively lift off and drop down said upper forming rollers over said lower forming rollers for disengagement and engagement respectively with the workpiece located over its associated lower forming roller.

2. A rolling mill system, according to claim 1, wherein all of said forming rollers act perpendicularly to the surface of the rolling material workpiece.

3. A rolling mill system, according to claim 1, including one additional lower forming roller carried on said lower frame member at the side thereof adjacent said grooving stand.

4. A rolling mill system, according to claim 3, wherein said one additional forming roller is mounted at a spaced location from the next adjacent one of said grooving rollers of said grooving roller stand by an amount which is substantially equal to four times the diameter of the finished rolled tube passing through said grooving stand.

5. A rolling mill system, according to claim 1, including means connected to said upper arm of said mounting frame for lifting said upper arm about its pivotal mounting to lift said forming rollers carried thereby off the workpiece.

6. A rolling mill system, according to claim 5, wherein said means for lifting said upper frame member of said mounting frame comprises a fluid operated piston and cylinder combination.

7. A rolling mill system, according to claim 1, including means connected to said mounting frame at a spaced location from the pivoting of said mounting frame for lifting and lowering said mounting frame.

8. A rolling mill, according to claim 1, wherein the entrance to said forming stand at an elevation corresponding to one half the diameter of the finished rolled tube passing through said grooving stand higher than the elevation of said center of said grooving stand.

9. A forming stand construction for use in association with a grooving stand, comprising a lower supporting arm pivoted at its one end, a plurality of lower forming rollers carried at spaced locations along said lower supporting arm, an upper supporting arm pivoted at an end thereof which is remote from the pivotal end of said lower supporting arm and pivoted at an end thereof which is remote from the pivotal end of said lower supporting arm, a plurality of upper forming rollers mounted on said upper supporting arm at spaced locations thercalong in a position for cooperation with the corresponding ones of said lower forming rollers on said lower supporting arm, and means connected to said upper supporting arm for raising the end of said upper supporting arm opposite to the pivotal end to permit engagement and disengagement of the upper forming rollers with the lower forming rollers.

10. A forming roller stand construction, according to claim 9, wherein said upper supporting arm and said lower supporting arm are part of a rectangular frame construction, and means connected to said frame construction for lifting said frame upwardly and downwardly to effect pivotal movement about said lower supporting arm.

11. A forming roller stand construction, according to claim 10, including an arm portion of said frame overlying said pivotal mounting of said lower supporting arm comprising a fluid cylinder having a piston slidable therein and a piston rod portion extending outwardly therefrom connected to said upper supporting arm for shifting said upper supporting arm upwardly and downwardly about its pivotal mounting. 

1. A rolling mill system for forming tubes, comprising a grooving stand having a plurality of upper and lower grooving roll sets between which a partly formed tubular workpiece is directed, a forming roll stand assembly including a mounting frame having an upper frame member and a lower frame member, said mounting frame being pivotally mounted adjacent the end thereof which is adjacent said grooving stand, a plurality of lower forming rollers mounted on said lower frame member, an upper forming roller associated with each of said lower forming rollers carried by said upper frame member, said upper frame member being pivoted at its one end and having an opposite end facing said grooving stand movable upwardly and downwardly to respectively lift off and drop down said upper forming rollers over said lower forming rollers for disengagement and engagement respectively with the workpiece located over its associated lower forming roller.
 2. A rolling mill system, according to claim 1, wherein all of said forming rollers act perpendicularly to the surface of the rolling material workpiece.
 3. A rolling mill system, according to claim 1, including one additional lower forming roller carried on said lower frame member at the side thereof adjacent said grooving stand.
 4. A rolling mill system, according to claim 3, wherein said one additional forming roller is mounted at a spaced location from the next adjacent one of said grooving rollers of said grooving roller stand by an amount which is substantially equal to four times the diameter of the finished rolled tube passing through said grooving stand.
 5. A rolling mill system, according to claim 1, including means connected to said upper arm of said mounting frame for lifting said upper arm about its pivotal mounting to lift said forming rollers carried thereby off the workpiece.
 6. A rolling mill system, according to claim 5, wherein said means for lifting said upper frame member of said mounting frame comprises a fluid operated piston and cylinder combination.
 7. A rolling mill system, according to claim 1, including means connected to said mounting frame at a spaced location from the pivoting of said mounting frame for lifting and lowering said mounting frame.
 8. A rolling mill, according to claim 1, wherein the entrance to said forming stand at an elevation corresponding to one half the diameter of the finished rolled tube passing through said grooving stand higher than the elevation of said center of said grooving stand.
 9. A forming stand construction for use in association with a grooving stand, comprising a lower supporting arm pivoted at its one end, a plurality of lower forming rollers carried at spaced locations along said lower supporting arm, an upper supporting arm pivoted at an end thereof which is remote from the pivotal end of said lower supporting arm and pivoted at an end thereof which is remote from the pivotal end of said lower supporting arm, a plurality of upper forming rollers mounted on said upper supporting arm at spaced locations therealong in a position for cooperation with the corresponding ones of said lower forming rollers on said lower supporting arm, and means connected to said upper supporting arm for raising the end of said upper supporting arm opposite to the pivotal end to permit engagement and disengagement of the upper forming rollers with the lower forming rollers.
 10. A forming roller stand construction, according to claim 9, wherein said upper supporting arm and said lower supporting arm are part of a rectangular frame construction, and means connected to said frame construction for lifting said frame upwardly and downwardly to effect pivotal movement about said lower supporting arm.
 11. A forming roller stand construction, according to claim 10, including an arm portion of said frame overlying said pivotal mounting of said lower supporting arm comprising a fluid cylinder having a piston slidable therein and a piston rod portion extending outwardly thErefrom connected to said upper supporting arm for shifting said upper supporting arm upwardly and downwardly about its pivotal mounting. 